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What happens during G1? - answer First growth phase; cell
synthesizes proteins and produces cytoplasmic organelles
What happens during the S phase? - answer Synthesis; continues to
grow as it copies chromosomes
What happens during G2? - answer Second growth phase; cell
completes preparation needed to divide and continues basic life of
the cell
What happens during mitosis? - answer Subdivided into prophase,
metaphase, anaphase, and telophase; nuclear division
What happens during cytokinesis? - answer Process of splitting the
daughter cells apart; splitting of cytoplasm and allocation of the
organelles and cytoplasm into each new cell
How does the number of chromosomes compare between G1 and
G2? - answer Remains the same
How does the amount of DNA compare between G1 and G2? - answer
G2 has double the amount of DNA (after S phase where
chromosomes are duplicated)
,What is the outcome of mitosis and why is this important? - answer
2 diploid daughter cells; creates more cells, regeneration,
replenishes old cells when they die; essential for growth and repair
in the body
What is the difference between a kinetochore microtubule and a
non-kinetochore microtubule? - answer Kinetochore microtubules
attach to the kinetochore of chromosomes whereas non-kinetochore
don't
What is the function of a kinetochore microtubule during mitosis? -
answer Where the spindle fibers attach during division to pull
chromosomes apart
What is the function of a non-kinetochore microtubule during
mitosis? - answer Responsible for elongation of cell during anaphase
Cytokinesis in animal cells - answer Formation of a cleavage furrow
which gradually "pinches" the cell in half
Cytokinesis in plant cells - answer Formation of cell plate that
gradually divides the cell in half - eventually thickens to form new
cell wall
Why is cytokinesis different in plants and animals? - answer Plant
cells have cell walls which are inflexible and cannot be "pinched in"
In an experiment, you fuse two cells, making 1 large cell with 2
nuclei. At the time of fusion, Cell 1 had been in mitosis and Cell 2
had been in the G1 phase. Predict what will happen to each of the
nuclei for Cell 1 and for Cell 2 after they have fused. - answer Cell 2
nucleus will immediately enter mitosis because the cell cycle is
driven by specific signaling molecules present in the cytoplasm and
Cell 1 would continue with mitosis
, What is the link between cyclins and MPF? - answer Cyclin is a
regulatory protein that a kinase must be attached to; MPF is made
up of cyclin combined with a CDK (cyclin-dependent kinase)
On a molecular level, what does a MPF molecule do? - answer
"Maturating-promoting factor;" Triggers the cell's passage past the
G2 checkpoint into the M phase (accumulation of cyclin proteins
combined with CDK to form MPF)
When during the cell cycle does production of cyclin really increase?
- answer Accumulated during G1 and S phase; increased during G2
prior to M phase (needs to make enough MPF to pass G2 checkpoint
and enter M phase)
What impact does a high concentration of MPF have on a cell? -
answer Triggers onset of mitosis; reduced at end of mitosis because
it depends on cyclin concentration
Interphase - answer Contains G1, S, and G2 phase; chromosomes
are not visible (instead in form of chromatin), make a copy of
themselves
Prophase - answer Copies of chromosomes fasten together; nuclear
membrane disappears; chromatin condenses into chromosomes;
centrosomes are pushed apart to opposite ends of the cell nucleus
by action of molecular motors acting on microtubules
Metaphase - answer Chromosomes line up along the center
metaphase plate; microtubules have found and attached to
kinetochores; centromeres convene themselves on metaphase plate
equidistant from 2 centrosome poles
Anaphase - answer Chromosomes split apart and are pulled to
opposite ends of the cell; break at centromeres and sister
chromatids move to opposite ends